Need help with Prodigy P3 brake controller

Discussion in 'Tires / Brakes / Bearings / Axles' started by Jeep Guy, Mar 23, 2018.

  1. Jeep Guy

    Jeep Guy Active Member

    Mar 7, 2018
    I recently bought a 2009 Starcraft pup and it has trailer brakes. I tow with a 4 door Jeep Wrangler and I installed the Mopar 7 pin wire harness. All of the lights on the camper work when plugged into the Jeep. Today, I installed the Prodigy P3 brake controller and it says no trailer connected. The blue wire on the controller is connected to the blue wire on the Mopar wire harness. I looked at the trailer wire harness connection and there is no corrosion. I have the controller connected to the brake wire at the pedal and I get a reading on the P3 when I depress the brake pedal. Anyone have any suggestions as to what the problem is?
  2. f5moab

    f5moab Retired from the Federal Government

    May 7, 2013
    Somewhere in Idaho
    Did you tell it that it would be connected to electric brakes? Page 8
    Otherwise, check continuity between the brake controller and the terminal end for the brake output to the trailer plug. If you can, apply 12 volts to the trailer connector terminal for the brakes and listen for the solenoid to engage each brake.
  3. giadiep

    giadiep Active Member

    Sep 5, 2015
    Syracuse, NY
    My story might help: I have a 2014 Durango that came with a 7 pin on the hitch and a pre-wired connector inside near the drivers side kick panel. I bought a prodigy and the correct wiring harness/adapter to connect it to the pre-wired connector. Everything worked except it would say “nc”. Dealer could not figure it out, RV place could not figure it out. Through tremendous internet research, it turned out that Dodge was missing a wire that would run from the pre-wired connector to the wire coming from the 7-pin harness (seems that they connect at a junction in the engine bay). I ran a separate wire connecting it to the wire coming from 7-pin to the wire going to the pre-wired connector inside the `drivers kick panel. Unfortunately I don’t remember which wire right now. This may not be your problem, but just throwing it out there. My hitch was factory. Just seems that dodge overlooked this wire on my car or that batch of cars. You may be able to find some info on a Jeep forum. Good luck.
  4. Jeep Guy

    Jeep Guy Active Member

    Mar 7, 2018
    Yes, I did tell the controller that I have electric brakes. I need to buy a multi tester to test for continuity. I will try to test the brakes from the trailer harness too.
  5. SteveP

    SteveP Well-Known Member

    May 21, 2015
    With your multimeter set for DC voltage probe the brake and ground poles, the 2 bottom poles, on the vehicle side of the connector. You should read some current even with the brakes not engaged, but you can tape the manual lever open just to make sure. If you get nothing there the problem's in the tv. Check the back of the connector and make sure the blue wire is continuous to the front of the truck. You may need to trace that wire all the way to the controller.
  6. nineoaks2004

    nineoaks2004 Every meal is a picnic and every Day is a holiday

    Oct 15, 2006
    Graceville, Florida
    Easy way to test if the magnets are activated is get someone to hold the activate lever on the controller, place a compass near the wheel, if energized the compass needle will deflect.
    Jeep Guy, PaThacker and NMroamer like this.
  7. Jeep Guy

    Jeep Guy Active Member

    Mar 7, 2018
    Thank you for the diagram. I got a multi meter and tested the brake wire and the ground and I am getting a reading on the meter. I looked around the camper yesterday and the wiring seemed to be in good shape. The camper is 10 years old so the brake assemblies could very well be bad. I will connect a wire from the battery to the brake wire at the trailer plug and see if anything happens. I probably need to pull the brake drum off and see what shape the brakes are in.
  8. myride

    myride Well-Known Member

    May 14, 2015
    Edmonton, AB
    I' following this with great problem is the same...except when I pull the breakaway switch the tailer brakes lock up. When p3 connected....won't recognize the trailer.
  9. Jeep Guy

    Jeep Guy Active Member

    Mar 7, 2018
    This weekend, I connected some wires directly to the camper battery and stuck them into the trailer tire harness on the brake blue wire and the common ground. The trailer brakes did not respond. I got under the trailer and pierced the brake wiring insulation with my multi-meter probes and I got no reading at all. So somewhere along the line, the wiring is not properly connected to the trailer brakes. How often do the 7-pin ware harnesses go bad?
    Last edited: Mar 26, 2018
  10. tenttrailer

    tenttrailer Art & Joyce - Columbus, O

    Jul 18, 2013
    Thornville, OH
    on the p3 you can display the output voltage. it should be somewhere between 6v and 12.xv when you engage the manual brake lever. The voltage will depend on the gain setting. If you have this I would think the controller is good. Now look at the current (amps) when you engage the manual lever. If you have near zero you have an open between the brakes and the controler. It should be somewhere between 2.0 and maybe 4.0a

    You can also display the input voltage and the brake light voltage. Input should be around the same as the tv battery and brake light should be 11.5 to 12.x which you will only see when the brake pedal is depressed.
  11. tombiasi

    tombiasi Well-Known Member

    Sep 1, 2012
    Northwestern New Jersey
    If your brakes are not connected the P3 is telling the truth.
    Fix the brakes.
  12. Wild-Life

    Wild-Life Active Member

    Jun 22, 2012
    North Carolina
    I would have an occasional red "no trailer" and had to replace the 7pin connector on the trailer pigtail. It had gone bad after 12 years. no recurrence of the problem in the last several years.
  13. Jeep Guy

    Jeep Guy Active Member

    Mar 7, 2018
    Well, I finally got my trailer brakes working. The brake controller and wire harness socket all tested fine so I moved to the inside of the camper and tested the wire harness where it came into the camper. It tested fine. So I ordered new 12 ga wire and new 7" brake assemblies from Etrailer. The wiring under the camper had been hacked up a bit by the previous owner. When I pulled the brake drum off, I found that the wiring to the electromagnet appeared to be melted right off of the magnet. And the brakes were made in 2006. 12 years ago. I got the new brakes installed and everything re-wired and I plugged it back into the Jeep to test it out and everything now works perfect.

    Rusty2192 likes this.

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